The present invention relates to an electrophotographic apparatus having a photoconductive element or similar image carrier and, more particularly, to a cleaning device for removing toner particles which remain on the image carrier after image transfer.
An electrophotographic copier, facsimile machine, laser printer or similar electrophotographic apparatus is extensively used which forms an electrostatic latent image on a photoconductive element, or image carrier, and develops the latent image by a developer such as a toner. In this kind of apparatus, after the transfer of the developed image or toner image to a paper sheet or similar recording medium, a part of the developer or toner is left non-transferred on the photoconductive element. The apparatus, therefore, usually includes a cleaning device for removing such residual toner particles from the photoconductive element. The cleaning device may be implemented by a cleaning blade which is made of polyurethan rubber, for example, and held in contact with the photoconductive element for scraping off the toner particles. Another implementation known in the art is the combination of a movable cleaning blade and a scraping member, as disclosed in Japanese Patent Laid-Open Publication (Kokai) No. 63-137279, for example. Specifically, while a cleaning member is movable between a first position where it contacts the photoconductive element and a second position where it is spaced apart from the same, there is a scraping member constituted by a polyester film (e.g. Mylar film available from Du Pont is held in contact with the cleaning blade). When the cleaning blade is moved from the first position to the second position away from the photoconductive element, the scraping member scrapes toner particles off the cleaning blade. A problem with this implemenation is that since the scraping member is fixed in place, the cleaning blade exerts a substantial load on the scraping member while removing residual toner particles from the photoconductive element in the first position. More specifically, the cleaning blade urges the scraping member downward. Such a load deforms the scraping member and thereby brings it out of accurate contact with cleaning blade as the time elapses, resulting in insufficient removal of residual toner.